As large grains easily settle in liquid, in some cases it is difficult to supply such grains to the area of a workpiece surface to be polished by abrasive polishing. The settling of large abrasive grains can be prevented by adding carboxymethylcellulose sodium (CMC-Na) to the polishing liquid. In this study, a light transmittance measurement device was developed to evaluate the settling characteristics of abrasive grains in CMC-Na aqueous solution. Using this device, we measured the changes in light transmittance over time for the suspension of green silicon carbide (GC) grains #600 in 0-1.0 wt% CMC-Na aqueous solution. The measurements showed that higher CMC-Na concentration reduced the settling of GC grains. To investigate the effectiveness of adding CMC-Na on the removal rate of polishing, acrylic resin flat plates were polished with a subaperture polishing tool in the polishing liquid, namely, a suspension of GC grains #600 with and without 1.0 wt% CMC-Na. The results demonstrate that the removal rate with CMC-Na is higher than that without it.

This paper discusses the effects of the wear behavior of grain cutting edges on the mechanism underlying generation of chatter vibration in creep feed grinding. Grinding wheels were polished using a diamond stick polisher, and an attritious wear flat area was formed on the tip of grain cutting edges. Creep feed grinding experiments were carried out using the polished grinding wheels. After the grinding process, the periodic line and specific peak frequency appeared and the generation of chatter vibration was confirmed. The peak frequency changed in proportion to the workpiece speed. These results revealed the relation between the generation of chatter vibration and the wear behavior of grain cutting.